1. Field of the Invention
The present invention generally relates to digital signal encoding and for this purpose provides a method and a device for encoding a digital signal.
The object of the encoding is to compress the signal, which makes it possible to transmit the digital signal and to store it in memory while reducing the transmission time, or the transmission rate, respectively by reducing the space in memory that is used.
The invention is in the field of lossy compression of digital signals. The digital signals considered here are of any type, for example fixed images, video, sound, or computer data.
In what follows, the encoding and decoding of a fixed image will more particularly be considered.
2. Description of the Related Art
In this context, certain encoding modes use a path established between a set of digital samples. For example, the French patent applications No. 01 06933 and 01 13922 concern such encoding modes.
For the encoding to be efficient, that is to say for it to have a good rate-distortion ratio, it is necessary to determine the path in an appropriate manner.
Techniques exist to determine a path between a set of samples. These techniques are known as techniques for solving the traveling salesman problem. A review of these techniques is for example set out in the work of Gerhard Reinelt entitled “The traveling salesman, computational solutions for TSP applications”, Springer-Verlag, 1994.